/* ═══════════════════════════════════════════════════════
   DESIGN SYSTEM — Black & White Minimalist
   ═══════════════════════════════════════════════════════ */

:root {
  /* Colors */
  --black: #0a0a0a;
  --white: #ffffff;
  --gray-50: #fafafa;
  --gray-100: #f5f5f5;
  --gray-200: #e5e5e5;
  --gray-300: #d4d4d4;
  --gray-400: #a3a3a3;
  --gray-500: #737373;
  --gray-600: #525252;
  --gray-700: #404040;
  --gray-800: #262626;
  --gray-900: #171717;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --section-py: clamp(4rem, 10vw, 8rem);
  --container-px: clamp(1.25rem, 5vw, 3rem);
  --container-max: 1100px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --duration: 0.5s;
}

/* ═══════════════ RESET & BASE ═══════════════ */

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--white);
  color: var(--gray-800);
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

/* ═══════════════ CONTAINER ═══════════════ */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--container-px);
  padding-right: var(--container-px);
}

/* ═══════════════ REVEAL ANIMATION ═══════════════ */

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children delay */
.reveal:nth-child(2) { transition-delay: 0.1s; }
.reveal:nth-child(3) { transition-delay: 0.2s; }
.reveal:nth-child(4) { transition-delay: 0.3s; }

/* ═══════════════ NAVBAR ═══════════════ */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem var(--container-px);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, padding 0.3s, background 0.3s;
}

.navbar.scrolled {
  padding: 0.75rem var(--container-px);
  border-bottom-color: var(--gray-200);
  background: rgba(255, 255, 255, 0.95);
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--black);
}

.dot { color: var(--gray-400); }

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-500);
  transition: color 0.3s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--black);
  transition: width 0.3s var(--ease-out);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--black);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Mobile toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--black);
  transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.open span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}
.nav-toggle.open span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ═══════════════ HERO ═══════════════ */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--white);
}

.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--gray-100) 1px, transparent 1px),
    linear-gradient(90deg, var(--gray-100) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(circle at center, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(circle at center, black 30%, transparent 70%);
  opacity: 0.7;
}

.hero-content {
  position: relative;
  text-align: center;
  padding: 6rem 0 4rem;
}

.hero-greeting {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-500);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.hero-name {
  font-size: clamp(2.5rem, 8vw, 5.5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--black);
  margin-bottom: 1.5rem;
}

.hero-typing-wrapper {
  font-family: var(--font-mono);
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--gray-600);
  margin-bottom: 1.5rem;
  min-height: 2rem;
}

.cursor {
  animation: blink 1s step-end infinite;
  color: var(--gray-400);
  font-weight: 300;
}

@keyframes blink {
  50% { opacity: 0; }
}

.hero-desc {
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  color: var(--gray-500);
  max-width: 540px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Scroll indicator */
.hero-scroll-indicator {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  animation: floatUp 2s ease-in-out infinite;
}

.mouse {
  width: 26px;
  height: 40px;
  border: 2px solid var(--gray-300);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 8px;
}

.wheel {
  width: 3px;
  height: 8px;
  background: var(--gray-400);
  border-radius: 3px;
  animation: scrollWheel 2s ease-in-out infinite;
}

@keyframes scrollWheel {
  0%, 100% { opacity: 1; transform: translateY(0); }
  50% { opacity: 0.3; transform: translateY(6px); }
}

@keyframes floatUp {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(-8px); }
}

/* ═══════════════ BUTTONS ═══════════════ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 2rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.3s var(--ease-out);
  letter-spacing: 0.01em;
}

.btn-primary {
  background: var(--black);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--gray-800);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.btn-outline {
  background: transparent;
  color: var(--black);
  border: 1.5px solid var(--gray-300);
}

.btn-outline:hover {
  border-color: var(--black);
  transform: translateY(-2px);
}

.btn-full {
  width: 100%;
}

/* ═══════════════ SECTION ═══════════════ */

.section {
  padding: var(--section-py) 0;
}

.section-alt {
  background: var(--gray-50);
}

.section-title {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 800;
  color: var(--black);
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--gray-500);
  max-width: 600px;
  margin-bottom: 3rem;
  line-height: 1.6;
}

/* ═══════════════ ABOUT ═══════════════ */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  margin-bottom: 1.25rem;
  color: var(--gray-600);
  font-size: 1rem;
  line-height: 1.8;
}

.about-text strong {
  color: var(--black);
  font-weight: 600;
}

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.stat-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s;
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.06);
}

.stat-number {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 500;
}

/* ═══════════════ TIMELINE ═══════════════ */

.timeline {
  position: relative;
  padding-left: 2.5rem;
  margin-top: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: var(--gray-200);
}

.timeline-item {
  position: relative;
  margin-bottom: 3rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-marker {
  position: absolute;
  left: -2.5rem;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--gray-300);
  background: var(--white);
  z-index: 1;
  transition: all 0.3s;
}

.timeline-marker.active {
  border-color: var(--black);
  background: var(--black);
  box-shadow: 0 0 0 4px rgba(0, 0, 0, 0.08);
}

.timeline-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 0.4rem;
}

.timeline-place {
  font-size: 0.9rem;
  color: var(--gray-500);
  font-style: italic;
  margin-bottom: 0.2rem;
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--gray-400);
  margin-bottom: 0.75rem;
}

.timeline-content p:last-child {
  color: var(--gray-600);
  font-size: 0.95rem;
}

.timeline-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  margin-bottom: 0.75rem;
}

.timeline-badge.current {
  background: var(--black);
  color: var(--white);
}

.timeline-badge.next {
  background: var(--gray-200);
  color: var(--gray-700);
}

/* ═══════════════ CERTIFICATIONS ═══════════════ */

.certs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}

.cert-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 14px;
  padding: 2rem;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s, border-color 0.3s;
}

.cert-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.07);
  border-color: var(--gray-300);
}

.cert-icon {
  width: 44px;
  height: 44px;
  margin-bottom: 1.25rem;
  color: var(--black);
}

.cert-icon svg {
  width: 100%;
  height: 100%;
}

.cert-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 0.6rem;
}

.cert-card p {
  font-size: 0.9rem;
  color: var(--gray-500);
  line-height: 1.6;
  margin-bottom: 1rem;
}

.cert-status {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
}

.cert-status.in-progress {
  background: var(--gray-900);
  color: var(--white);
}

.cert-status.planned {
  background: var(--gray-200);
  color: var(--gray-700);
}

/* ═══════════════ EXPERIENCE ═══════════════ */

.experience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.exp-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 14px;
  padding: 2rem;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s;
}

.exp-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.06);
}

.exp-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.exp-icon {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  color: var(--black);
}

.exp-icon svg {
  width: 100%;
  height: 100%;
}

.exp-header h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--black);
}

.exp-type {
  font-size: 0.8rem;
  color: var(--gray-500);
}

.exp-card > p {
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

.exp-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.exp-tags span {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.3rem 0.75rem;
  border-radius: 6px;
  background: var(--gray-100);
  color: var(--gray-700);
  border: 1px solid var(--gray-200);
}

/* ═══════════════ SKILLS ═══════════════ */

.skills-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.skills-cat-title {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gray-400);
  margin-bottom: 1.25rem;
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.tech-tag {
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  background: var(--white);
  color: var(--gray-800);
  border: 1px solid var(--gray-200);
  transition: all 0.3s var(--ease-out);
  cursor: default;
}

.tech-tag:hover {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
  transform: translateY(-2px);
}

/* ═══════════════ CONTACT ═══════════════ */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--gray-500);
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.85rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--black);
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: 10px;
  outline: none;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--black);
  box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--gray-400);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.contact-card {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 1.5rem;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 12px;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s;
}

.contact-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.05);
}

.contact-icon {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  color: var(--black);
}

.contact-icon svg {
  width: 100%;
  height: 100%;
}

.contact-card h4 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--gray-400);
  margin-bottom: 0.2rem;
}

.contact-card a,
.contact-card p {
  font-size: 0.95rem;
  color: var(--gray-800);
}

.contact-card a {
  transition: color 0.3s;
}

.contact-card a:hover {
  color: var(--black);
}

/* ═══════════════ FOOTER ═══════════════ */

.footer {
  padding: 3rem 0;
  border-top: 1px solid var(--gray-200);
}

.footer-content {
  text-align: center;
}

.footer-logo {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 1.25rem;
}

.footer-nav {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.footer-nav a {
  font-size: 0.85rem;
  color: var(--gray-500);
  transition: color 0.3s;
}

.footer-nav a:hover {
  color: var(--black);
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--gray-400);
}

/* ═══════════════════════════════════════════════════════
   RESPONSIVE — Fully mobile-first
   ═══════════════════════════════════════════════════════ */

@media (max-width: 900px) {
  .about-grid {
    grid-template-columns: 1fr;
  }
  .skills-container {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .experience-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  /* Mobile nav */
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: min(75vw, 320px);
    height: 100vh;
    background: var(--white);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    transform: translateX(100%);
    transition: transform 0.4s var(--ease-out);
    box-shadow: -10px 0 30px rgba(0, 0, 0, 0.08);
  }

  .nav-links.open {
    transform: translateX(0);
  }

  .nav-links a {
    font-size: 1.1rem;
  }

  /* Hero */
  .hero-content {
    padding: 7rem 0 4rem;
  }

  /* Stats */
  .about-stats {
    grid-template-columns: 1fr 1fr;
  }

  /* Certs */
  .certs-grid {
    grid-template-columns: 1fr;
  }

  /* Timeline */
  .timeline {
    padding-left: 2rem;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .about-stats {
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
  }

  .stat-card {
    padding: 1rem;
  }
}

/* ═══════════════ FORM SUCCESS STATE ═══════════════ */

.form-success {
  text-align: center;
  padding: 3rem 1rem;
}

.form-success-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 1.5rem;
  border-radius: 50%;
  background: var(--black);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: popIn 0.5s var(--ease-out);
}

.form-success h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 0.5rem;
}

.form-success p {
  color: var(--gray-500);
  font-size: 0.95rem;
}

@keyframes popIn {
  0% { transform: scale(0); }
  80% { transform: scale(1.1); }
  100% { transform: scale(1); }
}

/* ═══════════════ CUSTOM SCROLLBAR ═══════════════ */

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
  background: var(--gray-300);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--gray-400);
}

/* ═══════════════ SELECTION ═══════════════ */

::selection {
  background: var(--black);
  color: var(--white);
}